Electric furnace



L. FRIDERICH.

ELECTRIC FURNACE. APPLICATION FIL ED MAY 14. 1920.

Patented Oct. 31, 1922.

WWW 1 awvwwboz Z ML'J Frat/crack 8& it'd Gum/14124 4 Patented Get. 31, 1922.

UNITED STATES LOUIS FRIDERICH, OF PARIS, FRANCE, ASSIGNOR TO SOUTHERN POWER COMPANY, OF

PATENT OFFICE. A

NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

ELECTRIC FURNACE.

Application filed May 14,

To all whom it may concern:

Be it known that I, LoUIs Fmonmon, a citizen of Switzerland, and resident of Paris, France, have invented certain new and useful Improvements in Electric Furnaces, of which the following is a specifica- I tion.

My invention relates to furnaces, and especially to the type of electric furnace which is generally employed in the fixation of atmospheric nitrogen.

In the production of nitrogen oxide in furnaces of this type, it has been found that the return is substantially'increased when the gases are chilled from the very high temperatures enerated by the are down to about 1500 (1. One method of accomplishing this object is to provide a water jacket about the combustion chamber. In practice, however, the water in the jacket provides a ready ground connection for the current; and the arc, unless guided by special apparatus, tends tospring from the electrodes to the walls of the chamber, thus diminishing greatly the efiiciency of the arc, and tending to corrode the walls. I

It has also been ascertained in connection with furnaces of this type that the efliciency thereof is greatly increased by reducingthe size of the chamber in which the arc is formed. This fact, however, makes the employment of a water jacket especially diflicult, as the tendency of the arc to jump to the walls is naturally much greater in a small chamber.

An object of my invention is to overcome this difficulty by providing a furnace so constructed and arranged that suitable cooling means, such as a water jacket, may be em-- ployed, without interfering with the normal operation of the are.

A further object is to produce this result in such a way that a very small combustion chamber may be employed.

I also have provided a combustion chamher so designed and arranged that it may be made of very small size, without interfering with. the operation of the arc irrespective of whether a water jacket is used or not.

Other objects and advantages of my invention will be apparent from the following 1920. Serial No. 381.281.

description, taken in connection with the accompanying drawings, in which:

1 is a vertical sectional view, and

Flg. 2 is a transverse sectional view on line 22 of Fig. 1.

I employ suitable electrodes 10 which, in the form shown, are two in number and rectangular in cross-section, though obviously I may employ more thantwo electrodes, if desired. Electrodes 10 are connected to a suitable source of electric energy, as by wires 11, so that an arc will be developed between adjacent faces of the electrodes in the usual manner.

I enclose the u per ends of electrodes 10 in a suitable combustion chamber 12. This may be of various forms, though I prefer to employ the type shown, which is rectangular in form with the inner walls equally spaced. from the adjacent sides of the electrodes, permitting the maximum reduction in size of the chamber with a minimum liability of deflecting the arc. The chamber walls 12 may be composed of any suitable highly refractory and insulating substance, so that an intense heat may be developed within the chamber without damage to the walls. The electrodes 10 are preferably located. in the combustion chamber 12, both electrodes being spaced from the eduction end of the chamber to provide an eduction end free from electrodes. The electrodes 10 preferably extend into the chamber 12 through the induction end of said chamber.

I also employ a fiueor chaniber continuation 13, which preferably has inner walls 14-. continuous with the chamber walls 12, so as to form a direct passage from the combustion chamber through which the gases may pass after exposure to the arc.

In order to chill the ases leaving the combustion chamber, I pre erably provide means for cooling flue 13 through which the gases pass. For thispurpose, I preferably employ a water jacket of any desired type. One convenient arrangement for this purpose includes an outer wall 15 forming with the inner walls 14: of the flue a unitary construction, said inner and outer walls being water chamber or jacket, in which the coolingfluid 16 may be located. Suitable connections 17 and 18 are preferably provided. for maintaining a flow of water in the water jacket.

With this construction, it will be apparent that a very high degree of heat may be' maintained in the combustion chamber, which because of its arrangement and construction, may be of relatively small size, Without any danger of arc deflection due to the presence of a grounded Water jacket. However, the gases upon leaving the chamber are immediately subjected to the cooling effect of walls 14, which are maintained at a relatively low temperature owing to the circulation of Water 16. Moreover, this con struction is extremely convenient, readily manufactured and maintained; and the respective parts can readily be replaced without disturbing the remainder of the construction While I have referred to water as the cooling liquid, it will be understood that I do not consider my invention restricted to water, either in fluid or vapor form, as obviously other fluids may be employed.

While I have described the preferred form of my invention, it will be apparent that numerous variations therein may be made without departing from the spirit of my invention, as set forth in this specification.

I claim:

1. An electric arc furnace comprising a combustion chamber; said chamber being made of an insulating material, electrodes in said chamber; the said electrodes being located in said chamber spaced from the eduction end thereof and providing an eduction end. free from electrodes and a cooling chamber situated adjacent the said eduction end of the combustion chamber and communicating therewith.

2. An electric arc furnace comprising a combustion chamber; said chamber belng made of an insulating material, electrodes in said chamber, the said electrodes extend- -extending to a ing into the chamber from the induction end thereof and a cooling chamber situated udjacent the eduction end of the combustion chamber and communicating therewith.

3. An electric arc furnace comprising a plurality of electrodes, a combustion chamber surrounding the electrodes and a cooling chamber separated from the electrodes and situated adjacent the combustion chamber and communicating therewith; said cooling chamber comprising a flue forming a continuation of the walls of the chamber and a water jacket surrounding the flue.

4. An electric arc furnace comprising a.

combustion chamber said chamber belng non-conducting to prevent arc deflection, parallel electrodes enclosed by said chamber, said electrodes situated adjacent one end of the chamber, and a cooling chamber separated from the electrodes and situated adj acent the other end of the combustion chamber and communicatin therewith. 5. An electric arc urnace, including an elongated parallel sided combustion chamher, a pair of parallel electrodes each located symmetrically adjacent an end of the chamber, and flue having inner walls in continuation of the parallel sides, and, outer Walls spaced from and connected to the inner walls to form a. compartment for a cooling fluid int substantially spaced from the electro es.

6. An electric arc furnace comprising a combustion chamber; said chamber being made of an insulating material, electrodes in said chamber, the said electrodes being located in said chamber spaced from the eduction end thereof and providing an eduction end free from electrodes and acooling cham ber comprising a water jacketed flue mounted on said eduction end of the combustion chamber.

LOUIS FRIDERIGH.

Witness CLEMENT S. Enwanos. 

